US2655996A - Paraffin cleaner - Google Patents

Description

Oct. 20, 1953 c, w. EARL ET AL PARAFFIN CLEANER 2 Sheets-Sheet 2 Filed OCL. 4, 1951 C/mk/es Wfar/ BYm Patented Oct. 20, 1953 UNITED STA-res PATENT OFFICE Charles-W. Earl and WilliamH'. Middleton,- Seminole, Tex.

Application October 4, 1951,,Scria-1N'o. 249,738

6' Claims. 1

This-invention relates generally to' oil wells and pertains particularly to improvements inv paraifm cleaners.

A principal object of the present invention is to provide a paraffin cleaning or removing toolfor use-in a well tubing which is designed to move up and. down therein continuously by the employment of the fiowing. liquid. and gas in the well for elevating the implementvv and the action of gravity forreturm'ng it to the bottom of the well.

Another object of the invention is to provide an implement of the character stated which is raised in the well tubeby' thefiowing oil and gas acting against a. downwardly opening cup which follows the inside surface of the well tube, with means for contacting and, housing the cup when the tool reaches the top. of the well whereby the flow is permitted to. pass around the tube and the tool returns to the bottom. of the well by gravity.

Still. another object of the invention is to provide a. well tube cleaner of the character stated employing the liquid and gas flow for elevating the tool by imposing thrust against an expanded cup forming a part of the tool structure and engaging the inner surface of the well tube, with a trigger released spring actuated shield means which is of an outside diameter less than the inside diameter of the well tube and movesinto cup covering: and retracting position when the trigger strikes a closure member in the top of the well tube whereby thetool becomes free for return by gravity to the bottom of the well where the cup is. uncovered for repetition of the upward travel by the shock of striking either the bottom of. the well or a stop memberfixed in the tube.

Other objects and advantages of the invention will become apparent. as the description of the same proceeds and theinvention will be best understood from a consideration of the following detailed description. taken in connection with the accompanying drawings forming a part. of the specification, with the understanding, however; that the invention is not to-be limited to the exact details of. construction shown and. described since obvious modifications will occur to a person skilledin the art.

In the drawings:

Figure 1 is a view of theparaffin cleaner of the present invention, in side elevation, with thecup uncoveredready for the upward travel otthetool, the inside diameter of the well tube being, indicated, in dotted outline. v I I Figure 2 is. a view in side elevation of the tool turned 90, from the position shown in Figure. 1: and with the parts in the position assumed after. the tool has-reached the top of the well tubeiand is ready for descent under the action of gravity, the closed top of thewell above the lateral: outlet: pipe being shown. with: the: well tube in clotted outline.

Figures 3 and 3a show the toolin longitudinal sectiomthesectionbein'g taken. on theline 3-&' of Figure 1.

Figured is a transverse section taken substantially on. the line 4-4 of. Figure. 2..

Figure 51 is a longitudinal section. taken in the middle portion. of the tool substantially on: the line 55 of Figure 2.

Figure 6 is. a view in perspective of the" cup shield and trigger carrying rod;

Figure 7 is a longitudinal section through: the upper end. of the rod. showing the details of; the trigger mechanism..

Referring now moreparticularly to: the drawings the numeral it. inFigures 1 and: 2 designates the outline of the inside wallof a. well. tube in which the. tool operates. and. Figure 2; in. addition shows the top of the well with the lateral. fluid lead-oft designated l2 and a closurecap .L l over.-

. lying the top of the well. and; against which" the trigger mechanism. of. the tool strikes as. hereinafter described.

The paraiin cleanertool comprises an elongate housingv it which has a threaded socket. t8 in. its upper end and a threaded stem at its-lower end.

Secured. to the top end of the housing [615213116 tubular head unit 22. which has athreaded stem 24 on. its lower end for engagement in the socket [8. The bore 25 of the head is of slightly smaller diameter than the bore 26 of the-tubular housing I6, whereby the lower end of the threadedcoue pling stem 24. provides a downwardly facing.shoul der 2! at: thetop end of. the housing l6 for the purpose about to be described. I

The head unit 22 also functions as. a carrierrfor the arcuate scraping. blades 2 8. or paraffin knives. which are welded or otherwise secured to; the head-unit and extend in a. circumferential. direction; therearound.

The lower end of thehousing It. ha'scut there.- in the'opposite longitudinally extending. slots. 29: which open through-the lower end of the housing as shown in Figure- 5 and detachably connected to the lower endof the housing by the-threaded stem 20' is a tubular stop sleeve tirwhich-hasthe threaded socket 3i in its upper-end to receivethe stem 20. and which is also internally'threaded at its lower end as indicated at 3'2 to receive the threaded upper end of'a cup tube 3'31;

I Encircling the. cup tube as adjacent to the threaded upper end and slightly. below thethreads thereof, is a. wedge ring 34 which is fixedto tube 33. by welding or in any other suitable-manner.

The numeral. 35: designates afrustorconical, hollow. cup'member which has the smallerupper end portion in tight encircling relation with the tube 33- as shown in-Figure 3a; with thee opembase portion directed downwardly and with thetapcrect The cup 35 is preferably formed of a suitable oil resistant rubber such as neoprene, or of any other suitable material which will have sufficient flexibility to follow all of the uneven contours of the inner surface of a well tube and at the same time be compressible so as to have the diameter of the base portion reduced in the manner hereinafter described to permit the free falling of the tool through the well tube to the bottom of the well after it has been raised to the top by the action of the flowing liquid and gases pressing into the cup 35 while the periphery of the latter is in tight sliding contact with the tube wall.

Below the cup 35 the tube 33 carries a number of paraffin knives or scrapers 3? which are of the same form or construction as the scrapers 28 and these scrapers are preferably of the same character as those disclosed and claimed in allowed application Serial No. 131,486, filed December 6, 1949, now Patent No. 2,583,044.

Extending through the entire body of the tool, which body includes the housing is, the head unit 22, stop sleeve 30 and'cup tube 33, is a rod 38, the length of which is materially greater than the stated body portion of the tool.

A substantial portion of the lower end of the rod 38 is screw threaded as indicated at 39 and threaded onto this portion is a plug collar 55 which is adapted to enter the lower end of the cup tube where it closes such tube during the time that the tool is being forced upwardly in the well tube.

Also threaded upon the lower end of the rod 38 is a foot member tl which receives an upward blow by contact either with the bottom of the well or by a suitable stop member which may be fixed in the well tube at a desired elevation above the bottom. In Figure 1 the transverse dotted line 32 designates either the top of stop member fixed in the well tube or the bottom or floor of the well hole which the foot 41 strikes when the tool drops freely in the well tube.

Carried by and encirclin the rod 38 is the cylindrical cup shield 43 which is open top and bottom and which is attached to and maintained concentric with the rod by an elongate yoke 44 which comprises the two ear members 45 which are secured to the rod 38 and project diametrically from opposite sides thereof, and the legs 46, each of which is connected with the outer end of an ear and extends longitudinally of the rod, the other ends of the legs being attached to the edge of the cylindrical cup shield at the top end of the latter as shown in Figure 6.

As is clearly shown in Figures 1, 2 and 6 the yoke ears 55 he each in a slot 29 of the housing I6 and the yoke legs 45 are positioned upon the outer side of the stop sleeve 30 to extend longitudinally thereof and support the cylindrical cup shield in encircling relation with and spaced from the stop sleeve when the cup is extended for use as in Figure 1 or around the cup 35 and compressing the same to a reduced diameter when the cup is in retracted position in the sleeve for the descent of the tool into the well as shown in Figure 2.

The overall diameter of the cylindrical cup shield 43 is less than the inside diameter of the well tube so that there is clearance at all times around the shield thereby allowing for the free flow of liquid past the shield when the tool is descending in the well.

Encircling the rod 38, within the housing [6 and held in contact with and between the yoke ears 45 at its bottom end and the shoulder 2'! at its top end, is a spiral spring 48, the action of which will be hereinafter described.

The upper end of the rod 38 has formed therein from the end and opening through one side, a slot 39 in which is oscillatably supported on a transverse pin 50, a latch 5|, the lower end of which is normally urged outwardly beyond the periphery of the rod 38 by a spring 52.

Slidably supported in the upper end of the slot 59 above the latch 5l, is a trigger 53 which has limited longitudinal movement on a pin 54 extending transversely of the slot and passing through the short longitudinal hole 55.

The lower end of the trigger has an outwardly facing obliquely angled cam surface 55 which engages behind the upper end of the latch and the upper end of the trigger projects slightly above the upper end of the rod as shown in Figure 7. Accordingly it will be seen that when downward pressure is applied to the trigger 53 the cam 56 will cause the oscillation of the latch 5! to retract the lower end against the action of the spring 5'2, into the slot. This latch is adapted to extend beyond the top of the head unit 22 as shown in Figure 1 to hold the spring 48 compressed or under tension, at which time the rod 38 will be at the limit of its upward movement through the body portion of the tool so that the ears 55 will be in the upper end of the slots 29 and the cup will be below or out of the shield 53 as shown in Figure 1. This is the arrangement of the parts of the tool when the latter is being driven upwardly in the well tube by the force of rising fluid working against the cup, the periphery of the cup being in close sliding contact with the well tube wall.

When the tool reaches the top of the well tube the projecting end of the trigger 53 will strike the well tube cap I i with sufficient force to effect the retraction of the latch 5i whereupon the compressed spring will project the rod 38 downwardly carrying with it the cup shield 43, the plug collar 40 and the foot 4 When the shield is thus projected downwardly it will force itself over and around the cup 35, compressing and completely housing the latter, thereby moving the edge of the cup away from or out of contact with the well tube as illustrated in Figure 2. At the same time the plug collar 40 which previously had been tightly fitted in the lower end of the cup tube 33, when the tool was passing upwardly in the hole, is shifted downwardly to the position shown in Figure 2 so that the lower end of the tube 33 is opened. The tool is now free to fall or drop freely through the well to the bottom.

Vfhen the tool in falling freely, reaches the bottom of the well or reaches the stop member which may be at the level indicated by the dotted line 62 the force of the heavy tool coming suddenly to a stop in its descent will first check the downward movement of the rod 38 but the body portion of the tool will continue to move downwardly by inertia to the limit permitted by the slots 29. The ears 45 will then strike the upper ends of the slots 29 and stop the downward movement of the body portion of the tool, the spring 48 in the meantime becoming compressed. Such continued downward movement .of .the

body portion of the tool will also bring the latch 51 above the top end of the head unit 22, permitting the latch spring 52 to project the latch so that the compressed spring cannot then react to return the body portion of the tool to its for mer position on the rod 38.

As will be readily apparent when the above described action takes place the cup 35 will pass downwardly out of the shield 43 and into contact with the surface of the well tube and the plug collar =40 will be moved upwardly with the rod 33 to close the lower end of the cup tube 38 so that the well liquid and gases cannot pass upwardly through the tube 33 and escape above the cup 35 through the openings or slots 29. The tool will then be elevated by the action of the flowing well and any accumulated paranin on the surface of the tube will be removed by the knives or scrapers 28 and 31.

It will be seen from the foregoing that there is provided by the present invention an efficient paraifin scraper tool which operates entirely automatically to be elevated by no other force than the flowing well and returned to the bottom of the Well by no other force than the force of gravity. Consequently the tool after being put into the well tube will rise and fall repeatedly without attention as long as the well flows.

We claim:

1. A paraflin cleaner for flowing wells, comprising an elongate tubular housing, a rod extending therethrough and having a foot end and a head end, a cup of resilient material encircling and carried by the housing adjacent to the foot end of the rod, the cup opening downward and being of a diameter to fit the wall of the well pipe in which the cleaner is used, paraffin scrapers carried by the housing above and below the cup, 2. cup shield carried by the rod and encircling the housing adjacent to the cup, said rod being adapted to have longitudinal movement in the housing between a lower position relative to the housing in which said shield encloses and compresses the cup to a reduced diameter and an upper position relative to the housing in which the shield releases the cup for expansion of the cup to its full diameter, a spring means operativelv connected between the housing and the cup shield, said spring being under compression when the shield is in said upper position, and a latching mechanism for coaction between the rod and housing and including a movable element for coupling the rod and housing when the rod is in said upper position to maintain the spring under compression and a releasing trigger which when struck moves the element to uncouple the rod and housing to permit the spring to shift the shield to its lower position.

2. A gas and liquid actuated paraflin cleaner for flowing oil wells, comprising an elongate body, a cup carried thereby and ada ted to partition a well pipe in which it is positioned to receive thrust from the well flow to raise the body, means encircling the body and movable in one direction relative thereto to encircle and reduce the diameter of the cup and effect its separation from an enclosing well wall to permit the flow to pass the cup and permit the free falling of the cleaner in the well, scrapers carried by the body, means including a well bottom engaging element for efiecting the shifting of the cup encircling means to cup release position when the descent of the free falling cleaner is checked by engagement of said element with the well bottom, and means for effecting the reverse shifting of the cup' encircling means to said cup encircling position by forcible contact of a part of the top end of the cleaner with a top part of the enclosing well casing.

3. The invention as set forth in claim 2, wherein said body is tubular and said cup reducing means comprises a cylindrical shield encircling the body, said cup shifting means comprising a rod extending through and having limited free longitudinal movement in the body, the body having opposite longitudinal slots therein, elements carried by the rod extending through the slots and coupling the rod and shield together, said reverse shifting means comprising a coil spring within the body around said rod and compressed between the body and said elements and urging movement of the shield to cup encircling position, and a latch means for releasably coupling the upper end of the rod and the body to hold the spring under compression.

4. A paraffin cleaner for an oil well including a body comprising an elongated tubular housing and a tubular head unit coupled to the top end thereof, the housing having opposite longitudinal slots therein opening through its bottom end, a stop tube coupled to the bottom end of the housing and closing the ends of the slots, a resilient and compressible cup encircling and carried by the stop tube, scrapers carried by the body at the top and bottom ends, a rod passing freely through the body and projecting beyond the top and bottom ends thereof, a cup encircling cylindrical shield encircling the body, means coupling the rod and shield together through said slots and limiting the up and down movement of the rod in the body, said shield when the rod is at the limit of its down movement enclosing and constricting the cup and being free of the cup when the rod is at the limit of its up movement, spring means Within the housing and compressed between said coupling means and the tubular head of the housing and urging the rod downward through the body, and a latch mechanism carried by the top end of the rod and comprising a latch pivoted to the rod for engagement with the head unit to hold the rod at the upward limit of its movement with the spring compressed and a release trigger slidably carried by the rod and projecting beyond the top end of the rod and adapted when shifted downwardly to actuate the latch to disengaged position.

5. The invention as set forth in claim 4, with a closure plug carried upon the lower end of the rod which enters and closes the bottom end of the body when the rod is moved to the limit of its upward movement.

6. The invention according to claim 5, with a foot member secured to the bottom end of the rod.

CHARLES W. EARL. WILLIAM H. MIDDLETON.

References Cited in the file of this patent UNITED STATES PA'I'ENTS Number Name Date 2,143,450 Pippenger Jan. 10, 1939 2,157,493 Miller et al May 9, 1939 2,216,674 Miller et al Oct. 1, 1940 2,257,080 Turner Sept. 23, 1941 2,326,528 Festervan et al Aug. 10, 1943 2,362,198 Gibson Nov. 7, 1944 2,583,044 Earl Jan. 22, 1952 2,636,565 Williams Apr. 28, 1953

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